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Archive for 7 agosto 2017

Street Image Compare: how to compare Google Street View and Mapillary in the same web page

7 agosto 2017 2 commenti

If you ask to a crowd of people if they use Google Street View, probably you’ll have a positive answer.

If you ask, to the same crowd of people if they use Mapillary, probably the positive answers will be much less.

Despite the fact Mapillary, with lower means and possibilities, is proposed as a “crowd” alternative to the BigG service, its diffusion is not yet widespread, although there are places on the Earth whose geo referred images are available on Mapillary platform and are not available on Google Street platform.

The question is: is it possible to know, for a specific place, if geo referred images are available in one of these platforms or in both and, in that case, compare them?

I became aware about this problem after seeing an email in an Italian forum on Geographic Free and Open Source software (Gfoss.it); I’ve searched on the web but not successful.

So, starting from the OSM Map Compare idea, I’ve decide to build something by myself and in this way Street Image Compare was created.

The application is very simple to use: for the same place you can compare Google Street View and Mapillary images (if they are both available) and “surf” on the streets having Google Maps and OpenStreetMap as reference.

The user can select the place in three different ways:

  • typing the place name
  • typing an address
  • typing the coordinates couple

The application use Google Maps geocoder as geocoding engine.

When you open the app on the web page with the two maps, Google Street View and Mapillary, you can navigate on the images using the little arrows that are shown on the images: on the maps you’ll see a marker that show your current position.

On the both maps, and using the right buttons, is also possible to click on a specific point where you want to positionate yourself.

It’s quite easy to show the availability of Google Street View images (you can move the pegman on the map and immediately are shown some blue lines that show where the Google Street View images are present or not …) ….

…. for Mapillary is available a button “ON/OFF Mapillary sequences” on OpenStreetMap that draws some blue lines which show where the Mapillary images are present or not.

So, now with Street Image Compare you can compare Google Street View and Mapillary for every place in the world !!!

Here you’re a user session little video

 

On a technical point of view these are the data / services used:

Beyond the mere comparison between two similar services (or, in any case with strong analogies …), that could be a coding exercise the application has some pratical use.

The pictures above are about Amatrice in Italy where last year, on August 24, 2016, there was a great earthquake: in this case you can compare places before and after the earthquake because after this event someone has captured and published the images on Mapillary platform.

You can move along Amatrice streets and the effect in really shocking !!

Starting from this example you can understand as, in case of natural events with big impacts, Mapillary, for its “crowd” nature, can be useful to capture images after the events and with Street Image Compare, you can immediately compare places before and after event. Very useful!

The application code is open source, available on GitHub, with MIT license.

Here you have some examples:

Note: thanks to Mariana Cristina Da Silva for the help on this post! 🙂

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